Aromatic esters of anthranilic acid

ABSTRACT

Normally solid crystalline polypropylene is stabilized by esters of anthranilic acid of the formula:   IN WHICH R is H or an alkyl group of 1 to 4 carbon atoms, R&#39;&#39; and R&#39;&#39;&#39;&#39; are H, alkyl groups of 1 to 20 carbon atoms, halogens, and alkoxyl groups of 1 to 20 carbon atoms, R&#39;&#39;&#39;&#39;&#39;&#39; is an alkyl group of 5 to 20 carbon atoms either straight or branched chain in structure, and Y is H or has the structure:   WHEREIN R&#39;&#39;&#39;&#39;&#39;&#39;&#39;&#39; is H or an alkyl group of 1 to 20 carbon atoms, X is -O-, -S-n, or   WHERE N AND N&#39;&#39; MAY BE THE SAME OR DIFFERENT AND HAVE A VALUE FROM 1 TO 5, SAID ESTER OF ANTHRANILIC ACID BEING PRESENT IN AN AMOUNT SUFFICIENT TO ENHANCE THE STABILITY OF SAID COMPOSITION AGAINST UV and heat degradation.

United States Patent [1 1 Adams 51 May 20, 1975 1 AROMATIC ESTERS OF ANTHRANILIC ACID [75] Inventor: John Howard Adams, San Rafael,

Related U.S. Application Data [60] Division of Ser. No. 227,609, Feb. 18, 1972, Pat. No. 3,758,437, which is a continuation-in-part of Ser. No. 102,968, Dec. 30, 1970, abandoned [52] U.S. Cl 260/471 R; 260/472; 260/570.5 R;

260/608; 260/609 R; 260/613 R [51] Int. Cl C07c 101/54; C07c 149/42 [58] Field of Search 260/471 R, 472

[56] References Cited UNITED STATES PATENTS 4/1964 Staiger et al. 260/471 R 9/1969 llly 260/162 Primary ExaminerLorraine A. Weinberger Assistant Examiner--Michael Shipper Attorney, Agent, or FirmG. F. Magdeburger; John Stoner, Jr.; S. R. LaPaglia [57] ABSTRACT Normally solid crystalline polypropylene is stabilized by esters of anthranilic acid of the formula:

in which R is H or an alkyl group of l to 4 carbon atoms, R and R are H, alkyl groups of l to 20 carbon atoms, halogens, and alkoxyl groups of l to 20 carbon atoms, R is an alkyl group of 5 to 20 carbon atoms either straight or branched chain in structure. and Y is H or has the structure:

HO R" H wherein R" is H or an alkyl group of 1 to 20 carbon atoms, X is O, S,,, or

where n and n may be the same or different and have a value from 1 to 5, said ester of anthranilic acid being present in an amount sufficient to enhance the stability of said composition against UV and heat degrada tion.

3 Claims, No Drawings AROMATIC ESTERS OF ANTHRANILIC ACID This application is a division of application Ser. No. 227,609, filed Feb. 18, 1972, now US. Pat. No. 3,758,437 issued Sept. II, 1973, which, in turn, is a 5 continuation-in-part of US. application Ser. No. 102,968, filed Dec. 30, 1970, and now abandoned.

FIELD OF INVENTION This invention relates to normally solid crystalline polypropylene compositions of enhanced stability containing aromatic esters of anthranilic acid as stabilizers and certain aromatic esters of anthranilic acid as novel compounds.

DESCRIPTION OF INVENTION The novel compositions ofthis invention comprise normally solid, substantially crystalline polypropylene and a minor proportion of ester of anthranilic acid having the general structure:

O I Q O n l Y NHR in which R is H or an alkyl group of l to 4 carbon atoms, R and R" are H, alkyl groups of l to 20 carbon atoms, halogens, and alkoxyl groups of 1 to 20 carbon atoms, R' is an alkyl group of 5 to 20 carbon atoms either straight or branched chain in structure, and Y is H or has the structure:

HO H 11 40 wherein R is H or an alkyl group of l to 20 carbon atoms, X is where n and n may be the same or different and have a value from 1 to 5, said ester of anthranilic acid being present in an amount sufficient to enhance the stability of said composition against UV and heat degradation.

The novel stabilizers of this invention are aromatic esters of anthranilic acid of the formula:

0 R lL-d R"' mm :Y a

in'which R is H or an alkyl group of 1 to 4 carbon atoms, R and R" are H, alkyl groups of 1 to 20 carbon atoms, halogens, and alkoxyl groups of l to 20 carbon atoms, R' is an alkyl group of 5 to 20 carbon atoms either straight or branched chain in structure, and Y has the structure:

Ho R" ll wherein R"" is H or an alkyl group of l to 20 carbon atoms, X is -0-, ts 4CH N(-CH and 4on where n and n may be the same or different and have a value from 1 to 5.

The aromatic esters of anthranilic acid of this invention are made by heating a mixture of a phenol with isotoic anhydride until the evolution of carbon dioxide ceases. The reaction is as follows:

The following examples illustrate the aromatic esters of anthranilic acid and normally solid, substantially crystalline polypropylene compositions containing them. Unless otherwise indicated, the proportions are on a weight basis.

Example 1 Preparation of 2,2'-Thiobis(4-octylphenol) Monoester of Anthranilic Acid 3 methanol to yield 1.3 g of 2,2-thiobis(4-octylphenol) monoester of anthranilic acid as light tan globules, melting point l55.5 l56.5C. Calculated for C H NSO C, 74.81; H, 8,43; N, 2.50; S, 5.70. Found: C, 74.55; H, 8.24; N, 2.51; S, 5.88

The infrared spectrum contained two sharp N-H bands at 3500 cm and 3380 cm, a small broad O-H band at 3425 cm, and an aromatic ester carbonyl band at 1,705 cm.

The UV spectrum contained two absorptions above 2,400 A: at 2,900 A (e 5,400) and 3,400 A (e 6,000).

Other aromatic esters of anthranilic acid were prepared by the general method described in Example 1. The compounds of the examples and their evaluation in normally solid, substantially crystalline polypropylene are set out in the following table.

chieved by blending the polymer and the ester in powder form in conventional powder blenders or by mixing them in conventional melt blenders. Minor amounts of other polymers, pigments, photostabilizers, oxidation stabilizers, heat stabilizers, dye acceptors, dyes, fillers, and the like may also be incorporated into these mixtures.

The normally solid, substantially crystalline polypropylene which is stabilized by the aromatic esters of anthranilic acid in accordance with this invention is a well-known commercial commodity. It is normally at least about 85% crystalline. It is essentially insoluble in refluxing heptanes.

As indicated in the above table, each of the aromatic esters of anthranilic acid was mixed with polypropylene powder at a concentration of 0.5 percent. The dry mixture was pressed into -mil thick sheets. These sheets TABLE 0.5% in Polypropylene Time to Sample Failure Example 138C Oven Number R R" R""" R""" Y Hr FS/BL, Hr

l H H 8 8 S* 615 1235 2 H H 8 H 20 1250 3 CH H 8 8 -S* 144 317 4 H Cl 8 8 S-* 750 167 5 H N0 8 8 S--* 960 8 6 H H 12 12 -S-S* 884 500 7 H H 8 t 8 CH NC- 126 473 H CH Numbers refer to number of carbon atoms in corresponding R' and R"" alkyl groups of structural formulae.

Phenolic group having the structure in the above formula were tested in an oven at 138C to determine their life as expressed in hours. The polypropylene sheets were also exposed to a fluorescent sunlamp-black light Weather-Ometer and flexed periodically to obtain a time to flexural failure.

While the character of this invention has been described in detail with numerous examples, this has been done by way of illustration only and without limitation of the invention. It will be apparent to those skilled in the art that modifications and variations of the illustrative examples may be made in the practice of the invention within the scope of the following claims.

What is claimed is:

1. Ester of anthranilic acid having the following structure:

Example mixed homogeneously with such polypropylene at concentrations of at least about 0.05 percent by weight and usually from about 0.05 to 0.50 percent by weight based on the polypropylene. Homogeneous mixing is a- Number R R R" R R" Y 8 H CH3 CH3 8 8 S* 9 CH3 CZHS CZHF, 12 12 S* 10 H CH3 CMHU 8 8 SS-* 1 1 C 11, C11 C 11,, 12 12 -s 12 C .211 CH; 8 12 -s in the above evaluation the FS/BL refers to the standard fluorescent sunlamp/Black Light Weather- 9 Ometer to give the hours exposure causing failure of the sample when 1t 15 flexed.

As already mentioned, the aromatic esters of anthranilic acid of this invention have a remarkable ability to NHR X enhance the resistance of normally solid substantially crystalline polypropylene to UV and thermal degrada- H0 RI I I 1 tion. In the preparation of suitable polypropylene compositions the aromatic esters of anthranilic acid are in which R is H or an alkyl group of 1 to 4 carbon atoms, R and R" are H, N0 alkyl groups of l to 20 carbon atoms or halogen,

6 R' is an alkyl group of 5 to 20 carbon atoms either where n and n are the same or different and have a straight or branched chain in structure, value from 1 to 5. R"" is H or an alkyl group of l to 20 carbon atoms, 2. The compound of claim 1 wherein X is S.

and B 3. The compound of claim 1 wherein R' and R"" X is S or 5 are alk l grou s of 8 carbon atoms each.

+ +cn u+cn y p 

1. ESTER OF ANTHRANILIC ACID HAVING THE FOLLOWING STRUCTURE:
 2. The compound of claim 1 wherein X is S.
 3. The compound of claim 1 wherein R'''''' and R'''''''' are alkyl groups of 8 carbon atoms each. 